Implantable neurostimulator adapters

ABSTRACT

An adapter for coupling a plug of an implantable neurostimulator lead extension to a connector port of a neurostimulator device includes an elongate body, a connector including a plurality of contacts coupled to a first end of the elongate body, and a housing including at least two ports coupled to a second end of the elongate body. The adapter connector contacts provide for electrical coupling within the device port, and the adapter housing ports are arranged to receive side-by-side connector terminals of the lead extension plug. Housing contacts within each port provide for electrical coupling with corresponding contacts of the connector terminals of the lead extension plug and are coupled to corresponding contacts of the adapter connector via conductors extending within the elongate body between the housing and the connector.

RELATED APPLICATION

The present patent application is a continuation of U.S. patentapplication Ser. No. 11/678,706, filed Feb. 26, 2007 and now issued asU.S. Pat. No. 7,594,828, which is hereby incorporated, by reference, inits entirety.

TECHNICAL FIELD

The present invention pertains to extending implantable neurostimulatorleads and more particularly to adapters for neurostimulator leadextensions.

BACKGROUND

Implantable neurostimulators can provide electrical stimulation for thetreatment of pain and/or various neurological disorders.Neurostimulators typically include one or more stimulation electrodeswhich may be implanted at specific sites along a spinal cord, aperipheral nerve, or in a brain of a patient; the one or more electrodesare typically mounted to an elongate lead body which carriescorresponding conductors for electrical coupling of the electrodes to aneurostimulator device. Because the neurostimulator device is usuallyimplanted in a subcutaneous pocket that is somewhat remote from thestimulation site, often times a lead extension is required to couple alead connector, which terminates a proximal end of the lead body, to thedevice. The extension provides an additional length of conductor(s) toreach the device for the electrical coupling of the one or more leadelectrodes. One or more connector terminals terminating a proximal endof the lead extension are configured to mate with correspondingconnector ports of the device.

In recent years, new models of neurostimulator devices have beendeveloped for increased functionality; modifications to the size and/orshape of these newer devices have been made, for example, to accommodateadditional components, while keeping a bulk of the devices to a minimum.In many instances, the modifications have been accompanied by changes tothe configuration of the connector ports of these devices so that theports are no longer compatible with connector terminals of leadextensions which were designed to couple with older style devices. Thus,for those patients who either require or desire that an older styledevice be exchanged for a newer device, there is a need for an adapterto couple the connector terminals of one or more previously implantedlead extensions to one or more ports of the newer device.

BRIEF DESCRIPTION OF THE DRAWINGS

The following drawings are illustrative of particular embodiments of thepresent invention and therefore do not limit the scope of the invention.The drawings are not to scale (unless so stated) and are intended foruse in conjunction with the explanations in the following detaileddescription. Embodiments of the present invention will hereinafter bedescribed in conjunction with the appended drawings, wherein likenumerals denote like elements.

FIG. 1A is schematic plan view of a human body showing various generalimplant locations for implantable neurostimulator systems.

FIG. 1B is a perspective view of a portion of an exemplary implantableneurostimulator.

FIG. 2A is a combination plan view and perspective view of aneurostimulator adapter and a corresponding neurostimulator device,respectively, according to some embodiments of the present invention.

FIG. 2B is a perspective view of a portion of the adapter shown in FIG.2A, according to some embodiments.

FIG. 2C is a plan view including a partial cut-away section of theadapter shown in FIG. 2A, according to some embodiments.

FIG. 3A is a plan view of a portion of a system including the adapterand device of FIG. 2A, according to some embodiments of the presentinvention.

FIG. 3B is a plan view of an exemplary implant configuration for theportion of the system shown in FIG. 3A.

FIG. 3C is an end view of the system configured as in FIG. 3B.

FIG. 4A is a plan view of a system including an adapter, according to analternate embodiment of the present invention.

FIG. 4B is a plan view of an exemplary implant configuration for theportion of the system shown in FIG. 4A.

FIG. 4C is a plan view including a cut-away section of the adapter shownin FIGS. 4A-B, according to some embodiments.

DETAILED DESCRIPTION

The following detailed description is exemplary in nature and is notintended to limit the scope, applicability, or configuration of theinvention in any way. Rather, the following description providespractical illustrations for implementing exemplary embodiments of thepresent invention. Examples of constructions, materials, dimensions, andmanufacturing processes are provided for selected elements, and allother elements employ that which is known to those of skill in the fieldof the invention. Those skilled in the art will recognize that many ofthe examples provided have suitable alternatives that can be utilized.

FIG. 1A is schematic plan view of a human body showing various generalimplant locations for implantable neurostimulator systems. FIG. 1Aillustrates three general types of neurostimulator systems includingdevices 10 each coupled to an elongate lead 11. A first of devices 10 isshown implanted in a pectoral region 12, for example, within asubcutaneous pocket, and corresponding lead 11 extending from device 10to a site within a brain 2; a second of devices 10 is shown implanted ina lower region 13 of the body, and corresponding lead 11 extending fromdevice 10 to a site along a spinal cord 3; a subcutaneous pocket inlower region 13 may be formed, in an anterior, abdominal area of thebody, or in a posterior, high buttocks area of the body. A third ofdevices 10 is shown implanted in a subcutaneous pocket form in a thighregion 14 of the body, and a corresponding lead 11 is shown extendingfrom device 10 to a peripheral nerve site in a leg of the body. Itshould be noted that any of the pockets in regions 12, 13, 14 may hold adevice coupled to a lead extending to any of the peripheral nerves, forexample, in either leg, in either arm, or in the neck or head. Althoughnot shown, those skilled in the art will understand that leads 11 eachinclude one or more electrodes in proximity to a distal end thereof.

As previously described, a length of each of leads 11 may be extended bya lead extension. FIG. 1B is a perspective view of device 10 and anexemplary lead extension 117. FIG. 1B illustrates device 10 including ahousing or can 110 and a connector module 120 coupled to can 110 andincluding two connector ports 102; can 110 houses a battery andelectronic circuitry necessary to provide electrical stimulationdelivered by the electrodes of leads 11. Those skilled in the artunderstand that electrical contacts within each of ports 102 areelectrically coupled, via hermetically sealed feedthroughs, to theelectrical circuitry housed within can 110. FIG. 1B further illustrateslead extension 117 including an elongate body 171, to which a plug 172is coupled at a proximal end, and to which a connector port 174 iscoupled at a distal end. A pair of connector terminals 175 is shownextending proximally from plug 172; each of connector terminals 175includes a terminal pin contact 176 and a contact surface 177, which isspaced apart from pin contact 176 along a length of the correspondingconnector terminal 175.

According to the illustrated embodiment, ports 102 of device connectormodule 120 are positioned to receive, for electrical and mechanicalcoupling, the pair of side-by-side connector terminals 175, and,extension connector port 174 is adapted to receive, for electrical andmechanical coupling, a lead connector, for example, an in-lineconnector, such as is known to those skilled in the art, whichterminates a proximal end of the lead and includes a plurality of spacedapart contacts. Those skilled in the art will appreciate that extensionport 174 includes a plurality of electrical contacts, which couple withthe contacts of the lead connector, when the connector is fully insertedin port 174, and which are each coupled either to a correspondingterminal pin contact 176 or to a corresponding contact surface 177 ofconnector terminals 175, via a corresponding elongate conductorextending within elongate body 171. Thus, when connector terminals 175are fully inserted into device ports 102, and the lead connector isfully inserted into extension portion 174, electrical stimulationtherapy may be delivered from device 10 to the one or more electrodes oflead 11, either implanted in brain 2, along spinal cord 3, or along aperipheral nerve (FIG. 1A).

FIG. 2A is a combination plan view and perspective view of aneurostimulator adapter 200 and a neurostimulator device 20,respectively, according to some embodiments of the present invention;and FIG. 2B is a perspective view of a portion of adapter 200. FIG. 2Aillustrates device 20, like device 10 (FIG. 1B), including a housing orcan 210 and a connector module 220, however connector module 220includes ports 202 which differ in individual size and configurationfrom ports 102 of device 10. According to embodiments of the presentinvention, when device 10 (FIG. 1B) is changed out for device 20, anadapter, for example, adapter 200, is necessary to provide a compatiblecoupling between one of ports 202 of device 20 and the previouslyimplanted extension 117.

With reference to FIG. 2A, adapter 200 includes an elongate body 271 towhich a connector 275, which is compatible with each of ports 202 ofdevice 20, is coupled; connector 275 is shown including eight contacts270, so it should be appreciated that each of ports 202 include acorresponding set of eight device contacts for electrical coupling withcontacts 270, when connector 275 is fully inserted therein. FIG. 2Afurther illustrates adapter 200 including a housing 24 coupled to adistal end of body 271; with reference to FIG. 2B, housing 24 includes afirst pair of ports 261A, 261B and a second pair of ports 262A, 262B,wherein each pair of ports is adapted to receive the pair of connectorterminals 175 of extension 117 (FIG. 1B). Although the figuresillustrate a preferred adapter embodiment including four ports forcoupling with a pair of lead extensions 117, it should be noted that thescope of the invention is not so limited; for example, an alternateembodiment of the present invention includes an adapter housingincluding only one pair of ports and a corresponding connector includingonly four contacts.

According to the illustrated embodiment, a group of eight conductors 280(FIG. 2B) extends within body 271 between connector 275 and housing 24;each of the eight conductors 280, for example, individually insulatedcable conductors, provide for electrical coupling between a contact 270and a corresponding housing contact, each of which is disposed withinone of ports 261A,B, 262A,B and will be described in greater detailbelow. Conductors 280 may extend within body 271 in either a straight orcoiled configuration, and body 271 may include either a single ormulti-lumen tube, for example, formed by an extrusion and/or moldingprocess from medical grade silicone, or polyurethane, or a combinationthereof. Conductors 280 are preferably formed from an MP35N alloy, whichis known to those skilled in the art; and each of conductors 280 iscoupled to a corresponding connector contact 270 by means known to thoseskilled in the art, for example, crimping and/or welding; and each ofconductors 280 is preferably individually insulated by an insulativejacket, for example, formed from a fluoropolymer or a polyimide.

FIGS. 2A-B further illustrate housing 24 including a first sidewall 251,a second sidewall 252 (opposite first sidewall 251—seen in FIG. 2C), afirst face 241, which extends between sidewalls 251, 252 and on whichopenings of ports 261A,B, 262A,B are located, a second face 242(opposite first face 241), and a third face 243, which extends betweenfirst face 241 and second face 242. According to the illustratedembodiment: first and second sidewalls 251, 252 each include arelatively flat outer surface extending alongside each of ports 261A,B,262A,B; first face 241 includes a first portion 211, on which openingsof ports 261A, B are located, and a second portion 212 recessed fromfirst portion 211, on which openings of ports 262A, B are located; and,second face 242 extends at an angle Y, for example, greater than 0degrees and less than 90 degrees, with respect to first face 241, andincludes a first portion 221 and a second portion 222 recessed fromfirst portion 221. FIGS. 2A-B further illustrate adapter housing 24including a hole 29, which extends through housing 24 from firstsidewall 251 to second sidewall 252, and is located in proximity to anintersection of second housing face 242 and third housing face 243. Hole29 may be used to facilitate securing, for example, via a suture, ofadapter housing 24 to tissue within an implant pocket, either alongsidedevice 20 or separate from device 20.

FIG. 2C is a plan view of a portion of adapter 200 including a partialcut-away section of adapter housing 24, according to some embodiments ofthe present invention. FIG. 2C illustrates each of ports 261A,B, 262A,Bincluding a spring-type housing contact 233, for example, a multi-beamcontact, which may be formed from stainless steel, MP35N alloy, titaniumor any other suitable material known to those skilled in the art, and aset screw-type housing contact, which may likewise be formed fromstainless steel, MP35N alloy, titanium or any other suitable materialknown to those skilled in the art, and which includes a set screw 301,302, 303, 304 mounted in a set screw block. FIG. 2C further illustratesa shaft of set screw 201 extending approximately parallel with firstface 241 of housing 24, while shafts of each of set screws 202, 203 and204 extend at an angle X, for example, greater than 0 degrees and lessthan 90 degrees, with respect to first face 241. An access port 301 forset screw 201 is shown located on third face 243; an access port 302 forset screw 202 is shown located on first portion 221 of second face 242;and access ports 303, 304 for set screws 203 and 204, respectively, areshown located on second portion 222 of second face 242. Those skilled inthe art will understand that access ports 301, 302, 303 and 304 provideaccess for a set screw wrench, to engage screws 201, 202, 203, 204, yetare sealed to prevent ingress of bodily fluids when adaptor 200 isimplanted; any suitable type of grommet known to those skilled in theart and through which a set screw wrench may pierce, may be employed byembodiments of the present invention. With reference to FIG. 2C, it maybe appreciated that the angled arrangement of set screws 202, 203, 204,in combination with the angling and contour of second face 242,contributes to a reduction in a bulk of housing 24 from a bulk thatwould have resulted if set screws 202, 203, 204 had been oriented in atraditional manner, for example, like set screw 201, such that theirshafts extended parallel to first face 241. Such a traditionalarrangement of set screws 202, 203, 204 would have forced an increasedfootprint of housing 24, for example, along second face 242 (to provideappropriately oriented access ports for the set screws along second face242), or would have forced an increased thickness of housing 24, betweensidewalls 251, 252 (to provide appropriately oriented access ports alongone or both of sidewalls 251, 252).

With reference back to FIG. 1B, it will be appreciated that, when eachconnector terminal 175 of extension plug 172 is fully inserted into acorresponding port of one of the pairs of ports 261A,B, 262A,B, eachcontact surface 177 mates with a corresponding spring contact 233 andeach terminal pin contact 176 is positioned to mate with a correspondingset screw 301, 302, 303, 304. It should be noted that the scope of thepresent invention is not limited to the illustrated types of contactsand alternate embodiments of the present invention may include any othertypes of contacts known to those skilled in the art. Although notlabeled in FIG. 2C, those skilled in the art will recognize a set ofsealing rings shown in each of ports 261A,B, 262A,B; the illustratedsealing rings are intended to provide electrical isolation between eachpin contact 176 and corresponding contact surface 177 of fully insertedterminals 175, but are not necessary elements for every embodiment ofthe present invention.

FIG. 2C further illustrates conductors 280 extending from body 271 intohousing 24, beneath third face 243 of housing 24, and conductor paths(not labeled) extending within housing from each of housing contacts233, 301, 302, 303, 304 toward third face 243. Those skilled in the artwill appreciate that each conductor 280 may be electrically coupled to acorresponding housing contact in a number of ways; for example, eachconductor 280 may be routed into housing 24 along a correspondingconductor path for direct coupling with the corresponding contact, forexample, via welding, or, a separate conductor may extend from eachcontact, along the corresponding conductor path to a correspondingcoupling plate located in proximity to third face 243 for coupling tothe corresponding conductor 280, for example, via welding. Those skilledin the art will further appreciate that appropriate electrical isolationmay be provided for each conductor within housing 24, either via aninsulative jacket formed about each conductor, or via insulative wallsformed within housing 24 between each conductor, or via a combinationthereof.

According to an exemplary embodiment of the present invention, housing24 is formed from medical grade silicone, preferably having a durometerof approximately 65 D. With reference to FIG. 2C, a reinforcing tubingor liner 290 that extends within hole 29 may be desirable, particularlywhen housing 24 is formed from a relatively soft material that requiresa harder interface, for example, for a suture to bear against; examplesof appropriate materials for liner 290 include, without limitation,polysulfone and a relatively hard durometer of polyurethane, forexample, 75 D. Housing 24 may be molded and the illustrated componentsassembled therein according to any suitable method known to thoseskilled in the art. According to an exemplary assembly method, a portionof housing 24 is molded with openings into which the components areinserted; conductors may be coupled to each of the housing contactcomponents either before or after insertion into the correspondingopening of the corresponding housing. After the conductors are routedalong the conductor paths, voids over and around each opening are filledin, either by a secondary molding process or manual injection of fillermaterial, for example, medical grade silicone.

FIG. 3A is a plan view of a portion of a system including device 20, twoextensions 117 (FIG. 1B), and adapter 200, which couples extensions 117to device 20, according to some embodiments of the present invention. Itshould be noted that, although device 20 has been illustrated having twoconnector ports 202, device need only have one of these ports 202. FIG.3A illustrates extension connector 275 (FIG. 2A) inserted into deviceconnector module 220, and each extension plug 172 plugged into adapterhousing 24. With reference to FIG. 3A, in conjunction with FIG. 2A, itmay be appreciated that, according to a preferred embodiment, secondportion 212 of first housing face 241 is recessed from first portion 211of first face 241 by a distance D that allows for surfaces 372 ofextension plugs 172 to be spaced apart from one another when connectorterminals 175 (FIG. 1B) are fully inserted into corresponding ports261A,B, 262A,B (FIG. 2B) of adapter housing 24.

According to some exemplary implant methods, extensions 117 are pluggedinto adapter 200, either before or after adapter 200 is plugged intodevice 20, and then device 20 is rotated around, per arrow W, andshifted alongside adapter 200 and extension plugs 172 such that elongatebody 271 of adapter 200, which extends from housing 24 in a same generaldirection that openings of ports 261A,B, 262A,B face (FIG. 2B), wrapsalongside plugs 172, for example, as is shown in FIG. 3B. A length ofelongate body 271 may be between approximately 10 centimeters andapproximately 20 centimeters to accommodate such an implantconfiguration. It should be noted that, due to the flexible nature ofadapter body 271 and extension bodies 171, in practice, the positionsand contour of each, along with positions of housing 24 and plugs 172,would not be limited to the illustrated configuration. An implanter maydesire to secure, for example, with a suture through hole 29, adapterhousing 24 to subcutaneous tissue within an implant pocket alongsidedevice 20 such that adapter housing 24 will remain behind device 20 inthe pocket, that is, at a deeper location in the body, for example, asillustrated in FIG. 3C, where item number 350 represents an exterior ofthe body, or skin. Such an arrangement is preferred if a battery ofdevice 20 has the capacity to be re-charged transcutaneously, and foradded protection of adapter 200 and extensions 117 from nicks and cuts,if, and when and explant of device 20 is required, at a later date. Withfurther reference to FIG. 3C, in conjunction with FIG. 2B, it may beappreciated that a maximum thickness of housing 24, as defined betweenouter surfaces of sidewalls 251, 252, is kept to a minimum by thearrangement of ports 261A,B, 262A,B and set screws 201, 202, 203, 204,as previously described; according to exemplary embodiments, the maximumthickness of housing 24 is no greater than approximately 0.3 inch,preferably being between approximately 0.22 inch and approximately 0.27inch.

According to alternate implant methods, adapter 200 may be implanted ina first subcutaneous pocket and device 20 in a second subcutaneouspocket; for example, the first pocket may be one previously formed for adevice which has been explanted to be exchanged for device 20, and thesecond pocket, a new pocket formed for device 20. With reference back toFIG. 1A, the first pocket may be in pectoral region 12 and the secondpocket in lower region 13 or thigh region 14. For such an implantconfiguration, in which there is a relatively significant distancebetween the two pockets, a length of adapter body 271 may be greaterthan approximately 40 centimeters, upwards to approximately 110centimeters.

FIG. 4A is a plan view of a portion of another system including device20, two extensions 117 and an adapter 400, which couples extensions 117to device 20, according to alternate embodiments of the presentinvention. FIG. 4B is a plan view of an exemplary implant configurationfor the portion of the system shown in FIG. 4A; and FIG. 4C is a planview including a cut-away section of adapter 400. FIGS. 4A-C illustrateadapter 400 including a housing 24′ coupled to a first end of anelongate body 271′; and, although not seen, it should be understood thata connector, similar to connector 275 (FIG. 2A-previously described foradapter 200), is coupled to a second end of body 271′, which is shown(FIG. 4A-B) inserted within one of ports 202 of device header 220.Although not shown, conductors 280 extend within body 271′, which may beof similar in length and construction as that previously described forbody 271 of adapter 200. According to the illustrated embodiment,adaptor 400, like adapter 200, includes first and second pairs of ports261A,B, 262A,B, each of which receive a corresponding connector terminal175 (FIG. 1B) of extension plugs 172; furthermore, like housing 24 ofadapter 200, housing 24′ of adapter 400 includes first and secondsidewalls 251, 252, first face 241 on which openings of ports 261A,B,262A,B are located, second face 242 on which access ports 302, 303, 304for set screws 202, 203, 204, respectively, are located, and third face243 on which access port 301 for set screw 201 is located. Adapterhousing 24′ differs from adapter housing 24, in that elongate body 271′extends from second face 242 of housing 24′ in a direction which isapproximately opposite to a general direction in which each of theopenings of ports 261A,B, 262A,B face. Comparing FIG. 4C with FIG. 2C,it should be noted that, aside from conductor routing toward thatportion of second face 242 from which body 271′ extends, the arrangementof ports 261A,B, 262A,B and contacts 233, 201, 202, 203, 204 withinhousing 24′ of adapter 400 is very similar to that for housing 24 ofadapter 200. Thus, it may be appreciated that a bulk of adapter housing24′ does not differ significantly, in footprint or thickness, from thatof adapter housing 24.

FIGS. 4A-B further illustrate an exemplary implant method, whereindevice 20 is rotated around, per arrow W, and shifted alongside adapter400 and extension plugs 172 such that adapter body 271′ wraps alongsidedevice 20. As previously noted, in conjunction with FIG. 3B, due to theflexible nature of adapter body 271′ and extension bodies 171, inpractice, the positions and contour of each, along with positions ofhousing 24′ and plugs 172, would not be limited to the configurationillustrated in FIG. 4B. FIGS. 4A-C further illustrates elongate body271′ including a thickened or reinforced zone, in proximity to housing24′, wherein a groove 39 is formed; the thickened portion and associatedgroove 39 may be used to accommodate a suture for securing of adapter400 to subcutaneous tissue. Alternate implant arrangements of device 20and extensions 117 coupled together by adapter 400 may include those aspreviously described for device 20 and extensions 117 coupled togetherby adapter 200.

In the foregoing detailed description, the invention has been describedwith reference to specific embodiments. However, it may be appreciatedthat various modifications and changes can be made without departingfrom the scope of the invention as set forth in the appended claims.

1. An adapter for coupling a plug of an implantable neurostimulator lead extension to a connector port of a neurostimulator device; the plug including first and second connector terminals extending side-by-side; each of the first and second connector terminals of the plug including a terminal pin contact and a contact surface spaced apart from the pin contact along a length of the corresponding connector terminal; the adapter comprising: an elongate body and a plurality elongate conductors extending therein; a connector coupled to the elongate body, the connector including a plurality of contacts, each of the plurality of connector contacts for electrical coupling with a corresponding device contact mounted within the connector port of the device and each of the plurality of connector contacts coupled to a corresponding conductor of the plurality of elongate conductors; and a housing coupled to the elongate body and including a first sidewall, a second sidewall, a first face extending between the first and second sidewalls, a second face opposite the first face and extending between the first and second sidewalls, a third face extending between the first and second sidewalls and between the first and second faces, and a pair of housing ports, each port of the pair of housing ports including an opening and a first housing contact and a second housing contact; wherein both of the pair of port openings face in a same general direction and are located on the first face of the housing; the first housing contact of each of the pair of housing ports comprises a set screw mounted in a set screw block, and the housing further comprises an access port for a first of the set screws located along the third face, and an access port for a second of the set screws located along the second face; and each port opening provides for insertion of the corresponding connector terminal of the extension plug into the corresponding housing port for electrical coupling of the pin contact of each plug connector terminal with the corresponding first housing contact, and electrical coupling of the contact surface of each plug connector terminal with the corresponding second housing contact.
 2. The adapter of claim 1, wherein the first and second sidewalls define a maximum thickness of the housing that is no greater than approximately 0.3 inch.
 3. The adapter of claim 1, wherein the elongate body has a length between approximately 10 centimeters and approximately 20 centimeters.
 4. The adapter of claim 1, wherein the elongate body has a length greater than approximately 40 centimeters.
 5. The adapter of claim 1, wherein the second face extends at an angle greater than 0 degrees and less than 90 degrees with respect to the first face.
 6. The adapter of claim 1, wherein: the first of the set screws is mounted such that a shaft of the first set screw extends approximately parallel with the first face of the housing; and the second of the set screws is mounted such that a shaft of the second set screw extends at an angle greater than 0 degrees and less than 90 degrees with respect to the first face of the housing.
 7. The adapter of claim 1, wherein the housing further includes a hole extending therethrough from the first sidewall to the second sidewall.
 8. The adapter of claim 7, wherein the hole is lined with a reinforcing material.
 9. The adapter of claim 7, wherein the hole is located in proximity to an intersection between the second and third faces of the housing.
 10. The adapter of claim 1, wherein the elongate body extends from the housing to the connector in the same general direction in which the housing port openings face. 